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Fencer Vulns
medium 4.4

CVE-2020-11935 json

aufs: improperly managed inode reference counts in the vfsub_dentry_open() method

published 2023-04-07 3 y ago modified 2026-06-17 4 mo ago also EUVD-2020-4272

cvss
4.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

It was discovered that aufs improperly managed inode reference counts in the vfsub_dentry_open() method. A local attacker could use this vulnerability to cause a denial of service attack.

Patch / fix

  • linux Ubuntu 16.04 LTS 4.4.0-186.216
  • linux Ubuntu 18.04 LTS 4.15.0-112.113
  • linux Ubuntu 20.04 LTS 5.4.0-42.46
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1111.123
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1079.83
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1020.20
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1080.90~16.04.1
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1021.21

ubuntu advisories UBUNTU-CVE-2020-11935

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-11935 updated cvss 0.0

kernel: panic hit by kube-proxy iptables-save/restore

  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, kernel-alt, python-perf, +9 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise MRG 2 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.4 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Ubuntu Linux kernel (aufs filesystem module)

Classification

Weakness
  • CWE-911 Improper Update of Reference Count

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.